Fabrication and optical properties of highly transparent MgO ceramics by spark plasma sintering

Highly transparent MgO ceramics have been prepared via Spark Plasma Sintering (SPS) at 1200 degrees C for 10-60 min, under a pressure of 100 MPa. All of the prepared ceramics were visually transparent and exhibited relatively high in-line transmittance. The ceramic sintered for 60 min demonstrated the highest in-tine transmittance, of 60-80% in the 300 nm to 9 mu n wavelength range; values that are close to that reported for MgO single crystals. Photoluminescence measurements revealed a peak located at similar to 360 nm, which was determined to be due to oxygen vacancy color centers induced by the reducing atmosphere of the SPS process in vacuum atmosphere. (C) 2018 Published by Elsevier Ltd on behalf of Acta Materialia Inc.